A modern jointing system for medium voltage distribution cables

The 11 kV distribution networks operated by UK Regional Electricity Companies (RECs) have for many years employed a bitumen-filled jointing system which has proved to be both reliable and cheap. The traditional jointing methods inherent in this system are, however, highly skilled, time-consuming and require the craftsmen to handle hot compound and molten plumbing and soldering metals. Alternative jointing systems have been available for more than fifteen years but RECs have been reluctant to change because the alternatives tended to be expensive and did not provide a full range of products. RECs were also conservative in their attitude towards change. Emphasis was placed on material cost savings rather than the effect any changes might have on the total installed cost. The authors discuss NORWEB´s move away from traditional medium voltage jointing and the factors which were influential in the choice of a new system employing mechanical conductor connectors, heat-shrink insulation and resin encapsulation